Everyone has an opinion on this and guess what, most of us believe that we're doing the best thing. So, here's what I use.
First, I have no decals, just full body paint and clear coat.
I wash with Meguiars Gold car wash
https://www.meguiars.com/automotive/...4-64-oz-liquid and I "wax" with Wash-Wax-All. it's not super long lasting as it's not really a wax. But it's so easy to apply that I can do it nearly every time I wash the RV.
https://washwax.com/products/wash-wa...s-car-wash-kit
Also, I bought a SimpleChuck water deionizer to wash the RV with because drying with towels was more work than washing. And now, I don't have to towel dry because there are no water spots.
https://simplechuck.com/